Current battery internal heat exchangers require numerous components and sealing connections, and complicated manufacturing processes. One known method for cooling battery cells is to bring two cells into face contact with a cooling fin through which coolant flows. The cooling fins are connected by integrating an inlet and outlet header hole on both sides (or both on one side) of the fin. The inlet and outlet headers are then formed by stacking two or more fins together, and connecting the inlet and outlet header holes. An o-ring seal (or similar seal) may be used to form the seal between two fins. The seals for both inlet and outlet are typically integrated into a frame, which holds the cells and fins in place in the stack.
An example of this type of system is shown in FIG. 1. An expanded view of the battery pack 10 is shown. The battery cells 15 are separated by cooling fins 20. There is a cooling inlet 25 on one side of the cooling fin 20 and a cooling outlet 30 on the other side of the cooling fin 20. Coolant flows through channels 35 in the cooling fin 15. Heat from the battery cells 15 is conducted into the cooling fins 20. Two battery cells 15 and a cooling fin 20 can be contained in a frame 40. There are seals 45 on both sides of the cooling fin 15 for the cooling inlet 25 and cooling outlet 30. The seals 45 can be integrated into the frame 40. This arrangement requires multiple components and seals and a complicated assembly process.